Problem with mounting the installation tree for creating new VM on FC7!

hi all!
i'm trying to install a new xen virtual machine on FC7, using virt-manager.
the wizard finishes successfully and it start to create a VM, the installation tree has
been placed on host drive and shared using NFS, however installing a guest's linux
starts but it couldn't mount the installation tree with the error "that directory
could not be mounted from the server"!?  
system specifications are:


[root@localhost ~]# uname -r
2.6.20-2925.9.fc7xen



[root@localhost ~]# rpm -qa \*xen*
xen-libs-3.1.0-0.rc7.1.fc7
xen-3.1.0-0.rc7.1.fc7
kernel-xen-2.6.20-2925.9.fc7


mounting from the host to itself with NFS is OK with this command:


[root@localhost ~]# mount -t nfs 192.168.100.99:/root/Desktop/fc7/ /root/Desktop/test1/


where 192.168.100.99 is the host IP and /root/Desktop/fc7/ is the address of installation
tree on it!
i don't know the problem is with NFS, permissions or any thing else!
if more information is needed please just notify me, any advise, comment or solution is
helpful!

thanks,


Zahra Zojaji

________________________________________________________________________
Check Out the new free AIM(R) Mail -- Unlimited storage and industry-leading spam and
email virus protection.